A novel glucose sensor based on immobilization of glucose oxidase on the chitosan-coated Fe3O4 nanoparticles and the luminol-H2O2-gold nanoparticle chemiluminescence detection system

A novel and efficient glucose biosensor based on the chemiluminescence (CL) detection of enzymatically generated H2O2 was constructed by the effective immobilization of glucose oxidase (GOX) on the Fe3O4-chitosan (Fe3O4-CS) nanoparticles support. The covalent immobilization of enzyme was performed using glutheraldehyde (GA) as a cross-linking agent. (H2O2 was constructed by one covalent immobilization of glucose oxidase in glutaraldehyde-functionalized glass cell). In addition to catalyzes the luminol CL reaction, gold NPs offer excellent catalytic activity toward hydrogen peroxide generation as a result of enzymatic reaction between glucose oxidase and glucose. Based on response surface methodology (RSM), the optimal immobilization conditions for glucose oxidase were obtained as: enzyme to support ratio, 0.7; Immobilization pH, 6; cross-linking time, 75 min; and glutaraldehyde (GA) concentration, 0.2%. The characterization of Fe3O4, Fe3O4-chitosan and Au nanoparticles was analyzed by XRD, FT-IR and SEM. The linear range of this novel method is 1 x 10(-4) to 8.5 x 10(-7) mol L-1 (R-2 = 0.9956). The detection limit is 4.3 x 10(-7) mol L-1. The relative standard deviation (RSD) <3.1% was obtained. (C) 2015 Elsevier B.V. All rights reserved.